A young man visits his friend Yuu very often. Against all odds, he doesn't go to his friend's house so much as to his aunt, Yuu. The protagonist and Yuu often have sex, and the boy is greatly aroused by the feeling that his friend could return at any moment. Suddenly, the plot goes back in time and we are shown a moment of Ryuichi, which is the name of the main character, Yuu and Yui playing together. Yuu, upon learning that Ryuichi is a virgin, attempts his virginity. Suddenly Yuu sneaks out of his rooms and tells him that he'll be back soon, but let them play a game of console in the meantime. Yuu hints that she wants sex, but Ryuichi resists, because she knows the girl has a husband. She tells the guy that her husband is a workaholic and pays no attention to her. She likes young boys better. After this sudden confession, they have very rough and passionate sex, after which the girl invites him to come visit again...